Plate Nº 10 · recorded October 10, 2026
Biology & EvolutionReported finding
Cellular Recycling Doesn't Simply Decline With Age, Study Finds
Sanford Burnham Prebys scientists found autophagy shifts with age by cell type and sex — not a simple decline — and exercise may restore youthful levels in older adults.
By James Calloway3 min read694 words
In brief
- The study, published in Aging Cell (2026), analyzed cells from 49 volunteers aged 23 to 72 with no chronic diseases.
- Autophagy declined in male skin cells, stayed stable in female skin cells and increased in female-derived induced neurons.
- In adults 70 and older, higher autophagy tracked with poorer physical function, including lower aerobic fitness and weaker grip strength.
- A 12-week mild exercise program in five participants aged 77–88 may have reduced blood-cell autophagy toward youthful levels.
- Autophagy gene expression levels did not correlate with directly measured recycling rates.
Autophagy, the cellular recycling process long assumed to fade with age, does not simply decline in healthy people, according to a study published in Aging Cell by scientists at Sanford Burnham Prebys Medical Discovery Institute. Instead, it changes differently in each cell type — and differently in men and women.
The finding matters because a slowdown in autophagy is considered one of the hallmarks of aging, and researchers increasingly hope to target it with new healthy-aging interventions. But the actual human evidence behind the "autophagy declines with age" idea, the authors argue, has been thin.
What did the researchers actually measure?
The team collected skin and blood samples from volunteers aged 23 to 72 who reported no chronic diseases. To broaden the range of tissues under examination, the scientists converted skin cells into induced neurons — lab-grown nerve cells reprogrammed from adult cells.
For each cell type, the researchers sequenced RNA transcripts, the molecular messages produced when genes are read to build proteins and other cellular machinery. This showed how age and cell type influenced the activity of autophagy genes. The team also used a separate technique to directly measure the rate of autophagy in the cells, letting them compare actual recycling activity against what gene expression alone would predict.
What did the results show?
The patterns broke cleanly along cell type and sex:
- Autophagy declined with age in male skin cells.
- It remained stable in female skin cells.
- It increased with age in female-derived induced neurons.
The researchers also found that higher or lower expression of autophagy genes did not correlate with the directly measured recycling rate. In other words, reading gene activity alone can mislead.
"We found that autophagic activity changes were not universal throughout the body and did not follow the idea that autophagy simply declines with age," said Caroline Kumsta, Ph.D., senior and corresponding author of the study and assistant professor in the Center for Cardiovascular and Muscular Diseases at Sanford Burnham Prebys.
"This shows that people using static measures such as transcription levels to infer what's happening with autophagy need to be really careful about their interpretations," said lead author Tatiana Moreno, Ph.D., a former graduate student in the Kumsta lab.
Could more autophagy actually be bad for older adults?
In an unexpected twist, the study linked higher autophagy to worse physical function in adults aged 70 and older, across all three cell types:
- Higher autophagy in blood cells correlated with lower aerobic fitness.
- Higher autophagy in skin cells correlated with higher body mass index (BMI).
- Higher autophagy in induced neurons correlated with weaker grip strength, lower metabolism and a higher resting heart rate.
"I think this is an important distinction that merits continued study, as it appears that increased autophagy flux may be good in younger people yet problematic in older people," Kumsta said.
These results are associations from a relatively small group of healthy volunteers, and the authors themselves frame them as preliminary. They do not establish that extra autophagy causes poorer function — only that the two travel together in this cohort.
Can exercise reset cellular recycling?
In a small pilot test, five participants aged 77 to 88 gave blood samples before and after a 12-week mild exercise program designed to prevent falls. The results suggest exercise may reduce autophagic activity in blood cells back toward more youthful levels while improving physical performance.
"It is exciting to have this exercise intervention that may have a positive effect on autophagy and healthy aging, and I'm really excited to see where that goes," Kumsta said.
With only five participants, the pilot cannot support firm conclusions. Larger studies with more participants and improved testing protocols are already underway, in collaboration with the Exercise and Physical Activity Resource Center at UC San Diego.
"Autophagy and aging are so much more nuanced than previously assumed," Moreno said. "To better translate autophagy research discoveries into potential therapies, we really need to understand what is happening on a cell-specific level and how it is affected by sex and age."
The paper, by Tatiana M. Moreno et al., appears in Aging Cell (2026), DOI: 10.1111/acel.70734.
via Medical Xpress (Source)
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